Anthony Hopkins is an unlikely heavy-metal fan, with director Sacha Gervasi crediting a rock band with helping him cast the great actor in “Hitchcock.” “The process of casting Anthony involved me showing up to an Italian restaurant in Beverly Hills petrified,” Gervasi told us at the Gotham Awards. “The first thing Anthony said to me is that he’d seen a movie I made called ‘Anvil’ three times. And then I knew . . . I’m in.” Gervasi got Anvil frontman Steve “Lips” Kudlow and Hopkins on the phone together. “They were just like old friends,” Gervasi said. “They were so vastly different on paper, but they are exactly the same personality. It was wonderful.”